Truck cranks but doesnt start

[SUBURBAN5]

I hear you. Mine covered by the carpet. If I had a Silverado. I make a hole in the bed. Bedline the bed and bedline the panel. I've seen some awesome looking panels. But that's just me lol. I helped my friend lift one side of the bed and swap the pumps. Thing is if the cab mounts are rotted or corroded goodluck

 

[obsguy124]

I hear you. Mine covered by the carpet. If I had a Silverado. I make a hole in the bed. Bedline the bed and bedline the panel. I've seen some awesome looking panels. But that's just me lol. I helped my friend lift one side of the bed and swap the pumps. Thing is if the cab mounts are rotted or corroded goodluck

They probably got a bit of rust on em but if all goes well that bed will come out.

 

[SUBURBAN5]

Well good luck keep us posted

 

[Schurkey]

Checked the timing on the distributor (timing is good)
Checked to see if I was getting spark (good)

What i'm thinking it could be are the injectors, a bad ECM since no codes are being given, or crank position sensor needs replacement.

Timing is NOT determined by distributor position. Timing is determined by the crank sensor, and the ECM. If you're getting spark, the crank sensor is likely fine.

Turning the distributor affects how close the plug wire terminals are to the rotor tip, so the spark will jump to the correct terminal with minimal resistance.

For the module its ohms to test I believe and for the ignition coil I believe it's long as its sparking.

There's no easy test for the module except to see if it makes sparks when triggered. Anything beyond that requires special testing equipment; and frankly, I don't trust that sort of equipment.

By comparison, testing the coil is very easy. Ohmmeter testing of primary and secondary windings, including to ground. The ohmmeter testing can show a coil is faulty. It CANNOT prove a coil is good.

After the coil passes the ohmmeter testing, you then connect a spark-tester. If the coil can pass the ohmmeter tests, and reliably fire the spark tester, it's likely good.

Use a spark tester calibrated for HEI when testing an HEI system. A "points-style" spark tester won't load an HEI coil enough.

https://www.amazon.com/Performance-...ywords=HEI+spark+tester&qid=1596678308&sr=8-6

I opened the distributor as well and everything looks good I even pulled it out to check the timing and its fine (I did mark it before taking it out so I dont lose timing). Anyway ill find a way to test the coil when I get home ill keep you updated.

Again...distributor position doesn't change timing.

I will try to prime the system to see if I can get it to start even just for a little bit but even if the fuel pump IS the problem dont you think the starter fluids would have worked? I sprayed some in and thats when it all backfired and smoke came out of the intake.

I'm surprised that adding starter fluid didn't allow the engine to run.

Have you performed a cranking compression test? Jumped timing chain wouldn't prevent spark, but it might change the valve timing enough to cause problems.

 

[alpinecrick]

Yeah ill most likely end up just lifting the bed, I dont feel like making a big ugly hole in the truck bed haha

Don't. Just drop the tank--it ain't that hard, and a whole lot easier than lifting the bed, cutting a hole in the bed, etc........

Hardest part is usually getting the filler ad vent hose off.

 

[stutaeng]

Lifting the bed on these GMT 400s is no joke. I helped my brother remove the bed off his '90 RCSB. 3 guys still struggled to lift and slide it back, LOL.

Luckily we were able to check for power at the fuel pump and ruled out bad pump. It's a TBI, but still, bed is heavy. No way I could have done that myself. Actually, he came over because the bed bolts had loctite, and needed an impact. At that point I think I told myself dropping the tank would have been the better option working alone.

 

[Schurkey]

Lifting the bed on these GMT 400s is no joke. I helped my brother remove the bed off his '90 RCSB. 3 guys still struggled to lift and slide it back, LOL.

No struggle at all...with the right tools.

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[454cid]

I've pulled my box twice....with help. It beats working under the truck trying to wrestle the tank and disconnect everything, but it's still a job. Another plus is that it gives a great chance to clean up the frame and replace the brake line.

 

[Crazydavez28]

Hey everyone!

I'm having some issues with my 1998 chevy silverado, one day I was just driving and it was running just fine but as I was coming off of a stop sign the engine immediately stopped and it was weird because all lights were still on and not even the check engine light came on. The engine cranks and its like it wants to start and I've tried using starter fluids but the engine would just backfire upon cranking. The computer did not give off any codes which is the weird part.

Here's what I've done so far to narrow the problem down:
Checked fuel pressure (holds around 50-54)
Checked the timing on the distributor (timing is good)
Checked to see if I was getting spark (good)

What i'm thinking it could be are the injectors, a bad ECM since no codes are being given, or crank position sensor needs replacement.

What do you guys think I should do? I'm really stuck here and I could really use some help so any advice would be appreciated!

Has it been damp out in your area? Starting fluid backfires can break the gear on the flexplate.
Sounds like the high mileage hard starting issue and not a fuel pump. First fully charge the battery, then I would recommend pulling the cap and rotor and clean out the distributor pickup and drill the vents out. You can also pull the crank sensor and clean it off but my issue didn't go away until I cleaned the distributor.

 

[PlayingWithTBI]

No struggle at all...with the right tools.

Looks like that bed weighs 1/2 as much as a normal bed would.

When we changed my pump we removed all but 1 bolt loose on the right side, tilted it up, and propped it with a 2X4.